81624672 has 84 divisors (see below), whose sum is σ = 241006500. Its totient is φ = 27200448.

The previous prime is 81624637. The next prime is 81624679. The reversal of 81624672 is 27642618.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81624679) by changing a digit.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 21579 + ... + 25077.

It is an arithmetic number, because the mean of its divisors is an integer number (2869125).

Almost surely, 2^81624672 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81624672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120503250).

81624672 is an abundant number, since it is smaller than the sum of its proper divisors (159381828).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81624672 is an equidigital number, since it uses as much as digits as its factorization.

81624672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3527 (or 3504 counting only the distinct ones).

The product of its digits is 32256, while the sum is 36.

The square root of 81624672 is about 9034.6373474534. The cubic root of 81624672 is about 433.7842868915.

The spelling of 81624672 in words is "eighty-one million, six hundred twenty-four thousand, six hundred seventy-two".